Mac mini sd card works with server but not OSX

I have a new Mac mini that came with server 10.6 preinstalled. I installed OSX 10.6.3 with a retail disk, and SD cards stopped being recognized. I installed all software updates but still no SD card reader.
I reinstalled OSX server, and the SD card came back. Is there a driver that needs to be installed that is not in the OSX retail disk?

Yes, I did run all software updates.*
I noticed however that the server os has a .kext file in the extensions folder that is missing in the osx extensions folder. I'm not at my computer now, but it was named something like "appleSD..."
I looked for documentation on how to install a .kext manually but all I found where articles related to osx86.*